Evaluation of the sintering properties of pottery bodies using terahertz time-domain spectroscopy

Abstract

Terahertz (THz) time-domain spectroscopy was applied to evaluate the sintering properties of pottery bodies. The transmittance, absorption coefficient, and refractive index of pottery bodies fired at various temperatures were evaluated over the THz frequency range of 0.3–1.3 THz, and the relationships between these properties and their sintering properties were examined. The absorption coefficient and refractive index at 0.5 THz were sensitive under sintering conditions. In particular, the sintering-temperature dependence of the refractive index in the THz region showed a similar trend to that shown by the bulk density. THz-wave two-dimensional imaging was used to visualize inhomogeneities inside the bodies. Our study demonstrated that THz-wave analysis can be used to manage the firing process of pottery and ceramics and to conduct nondestructive testing of products.

Keywords

• Terahertz time-domain spectroscopy
• pottery
• absorption coefficient
• refractive index
• water absorption rate
• bulk density